Fiat Seicento wheels are generally 13" or 14" as standard so these sizes are probably the best to use if you're buying after market. You can, however, go up to a 15" - but be warned, you may suffer from clearance issues! (maybe better to buy the wheels BEFORE you lower the car!).

The standard wheels are 5.5 wide.for easy fitment its best not to go beyond 6j though it is possible.

14" is generally regarded as the best compromise of size whilst keeping the handling/acceleration charcteristics of the car.

(on non sporting cinqs/sei's you must lower the car if fitting larger alloys. OE sporting springs are enough of a drop.this is by FIAT's recommendation)

now lets get onto offsets,spacers,centre bores etc.this is where people seem to struggle

fiat use a 58.1 centre bore(the hole in the centre).anything smaller will not fit bar paying a machine shop to machine the centre bore out.anything bigger will fit but must never be fitted without the appropriate spigot ring.this isnt a small matter,if the wrong or no spigot ring is fitted then the wheel can move around on the hub.this is extremely dangerous.

fiat use a 98 PCD(pitch circle diameter) so alloys listed with this PCD are a straight fit.you can go to 100PCD using wobbly bolts/nuts

offset(ET) on cinq/sei is around 30-38 for replacement alloys30.5 with a 3mm spacer at the front so an offset of 27.5 on OE alloys or for the sei abarth 36 but with an OE 10cm spacers at the front giving an offset of 26http://www.gomog.com/allmorgan/wheeloffset.htmloffset and PCD info

now PCD can only be 98 or 100.thats it nothing else.heres a list of various marques pcd's so you can see OE alloy fitments

offsets can vary but not too far.eg on your cinq your aiming for as close to OE as possible.

i'll try and give an example.you buy some spanking Compomotive Mo's in 14" @ 6J wide.they have an offset of ET35 so you fit 8mm spacers on the front bringing the offset down (you take the spacer size off the offset)

when fitting spacers over 5mm its really better(read safer)to fit hubcentric ones.if you use wider than standard spacers then remember you will need longer bolts to account for the spacer width.

Before you go through buying your wheels please check the pcd chart for offset and bore. This chart contains other vehicles on it so you can pick other wheels with the same pcd/offest/bore to get the right wheels for yourself.

hi, just wanted to say that I couldn't get hubcentric spacers less than 10mm. This is because the lip on the hub that centres the original wheels is 8mm. So the spacer has to fit on this and provide enough material to make the new lip without the transition metal being too thin. This was on a '99 sei 899cc sx.

Also, the acceleration/top speed is only affected if the total rolling circumference changes when putting on new wheels/tyres. A 15" wheel can maintain the original circumference if a low enough profile is used (your calculater lets you test this)